Final answer:
A capsulated bacterium has a tough outer layer made of polysaccharides, which aids in adherence to surfaces and provides extra protection against external threats, potentially making it more resistant to immune defenses and antibiotics.
Step-by-step explanation:
The true statement about a capsulated bacterium is that it has a tough outer layer. This protective capsule is typically made of polysaccharides and serves several functions: it enhances the bacterium's ability to adhere to surfaces in its environment, including host cells, it provides an additional layer of protection against desiccation, and it may help protect the bacterium from the host immune system. Contrary to assisting in combating antibiotics, the presence of a capsule can make bacteria more resistant to both the host's immune defenses and antibiotic treatment.